Technical Field
The present invention relates to a sludge recycling treatment system of an urban sewage plant, and in particular, to a device that processes wet sludge by combining closed solar sludge evaporation and drying, and rotary sludge roasting and activated carbon manufacturing.
Related Art
In the prior art of sludge evaporation treatment by solar energy, sludge is dried mainly by using a solar evaporator, which has such advantages as simplicity and practicality of devices, a short processing flow, and a good quality of discharged water, and has a disadvantage that conveyor belts of a solar sludge evaporation treatment device use materials of cloth and rubber, and the rubber is easily aged, thereby generating a new pollutant under a high temperature.
At present, there is no feasible method for achieving industrialization of activated carbon manufacturing from sludge. Because a moisture content of the sludge is high (about 80%), if a drying process with an external heat source is directly used for drying and activated carbon manufacturing, a heat energy consumed is excessively great and a processing cost is also very high. Moreover, hot humid air needs to be discharged during the drying process. The hot humid air has an excessively offensive odor, and a deodorization cost is also very high, so that process requirements and market demands cannot be satisfied. If a deep dehydration and drying process is used, many inorganic matters such as flocculants and lime need to be added during deep dehydration of wet sludge. After addition of the inorganic matters, pores are difficultly formed during activated carbon manufacturing, and an external heat source is further needed subsequently for drying. Therefore, the prior art is still not mature enough no matter in process or operation cost.